1、使用指定文件，創建表并插入數據：

文件，d:\MySQL_cookbook\limbs.sql

DROP TABLE IF EXISTS limbs; CREATE TABLE limbs (thing VARCHAR(20), # what the thing islegs INT, # number of legs it hasarms INT # number of arms it has );INSERT INTO limbs (thing,legs,arms) VALUES('human',2,2); INSERT INTO limbs (thing,legs,arms) VALUES('insect',6,0); INSERT INTO limbs (thing,legs,arms) VALUES('squid',0,10); INSERT INTO limbs (thing,legs,arms) VALUES('octopus',0,8); INSERT INTO limbs (thing,legs,arms) VALUES('fish',0,0); INSERT INTO limbs (thing,legs,arms) VALUES('centipede',100,0); INSERT INTO limbs (thing,legs,arms) VALUES('table',4,0); INSERT INTO limbs (thing,legs,arms) VALUES('armchair',4,2); INSERT INTO limbs (thing,legs,arms) VALUES('phonograph',0,1); INSERT INTO limbs (thing,legs,arms) VALUES('tripod',3,0); INSERT INTO limbs (thing,legs,arms) VALUES('Peg Leg Pete',1,2); INSERT INTO limbs (thing,legs,arms) VALUES('space alien',NULL,NULL);SQL 命令如下：

mysql> use cookbook;mysql> source d:/MySQL_cookbook/limbs.sql;SELECT 查詢驗證是否成功：

mysql> select * from limbs; +--------------+------+------+ | thing | legs | arms | +--------------+------+------+ | human | 2 | 2 | | insect | 6 | 0 | | squid | 0 | 10 | | octopus | 0 | 8 | | fish | 0 | 0 | | centipede | 100 | 0 | | table | 4 | 0 | | armchair | 4 | 2 | | phonograph | 0 | 1 | | tripod | 3 | 0 | | Peg Leg Pete | 1 | 2 | | space alien | NULL | NULL | +--------------+------+------+

2、指定用戶登錄，非root:

使用MySQL Command ?Line ?Client，一進入就是輸密碼（默認為root用戶），根本沒有選擇用戶的過程

Enter password: **** Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 38 Server version: 5.0.67-community-nt MySQL Community Edition (GPLType 'help;' or '\h' for help. Type '\c' to clear the buffer.
原來， 要能指定用戶是通過 cmd 進入的：

C:\>mysql -h localhost -u cbuser -pcbpass -D cookbook Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 41 Server version: 5.0.67-community-nt MySQL Community Edition (GType 'help;' or '\h' for help. Type '\c' to clear the buffer.

3、插入 SQL 類型為ENUM 和 SET 的數據（其實和操作字符串一樣）

文件，d:/MySQL_cookbook/profile.sql

DROP TABLE IF EXISTS profile; create table profile (id int unsigned not null auto_increment,name char(20) not null,birth DATE,color enum('blue', 'red', 'green', 'brown', 'black', 'white'),foods set('lutefisk', 'burrito', 'curry', 'eggroll', 'fadge', 'pizza'),cats int,primary key (id) );INSERT INTO profile (name, birth, color, foods, cats) VALUES('Fred', '1970-04-13', 'black', 'lutefisk,fadge,pizza', 0); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Mort', '1969-09-30', 'white', 'burrito,curry,eggroll', 3); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Brit', '1957-12-01', 'red', 'burrito,curry,pizza', 1); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Carl', '1973-11-02', 'red', 'eggroll,pizza', 4); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Sean', '1963-07-04', 'blue', 'burrito,curry', 5); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Alan', '1965-02-14', 'red', 'curry,fadge', 1); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Mara', '1968-09-17', 'green', 'lutefisk,fadge', 1); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Shepard', '1975-09-02', 'black', 'curry,pizza', 2); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Dick', '1952-08-20', 'green', 'lutefisk,fadge', 0); INSERT INTO profile (name, birth, color, foods, cats) VALUES('Tony', '1960-05-01', 'white', 'burrito,pizza', 0);

4、Using Prepared Statements and Placeholders in Queries

PreparedStatement s; s = conn.prepareStatement ("SELECT id, name, cats FROM profile WHERE cats < ? AND color = ?"); s.setInt (1, 2); s.setString (2, "green"); s.executeQuery ( );// ... process result set here ... s.close ( ); // close statement?? ? ?One of the benefits of prepared statements and placeholders is that parameter binding operations automatically handle escaping of characters such as quotes and backslashes that you have to worry about yourself if you put the data values into the query yourself.

?? ? Another benefit of prepared statements is that they encourage statement reuse.

?? ??A third benefit is that code that uses placeholder-based queries can be easier to read, although that's somewhat subjective.

5、Including Special Characters and NULL Values in Queries

（單引號[ ' ]；雙引號[ ?" ?]；反斜線[ ?\ ?]；二進制數據[ ?可能包含：單引號，雙引號，反斜線，null]）

?? ? ? a）：Use placeholders if your API supports them. Generally, this is the preferred method, because the API itself will do all or most of the work for you of providing quotes around values as necessary, quoting or escaping special characters within the data value, and possibly interpreting a special value to map onto NULL without surrounding quotes.

PreparedStatement s; int count; s = conn.prepareStatement ("INSERT INTO profile (name,birth,color,foods,cats) VALUES(?,?,?,?,?)"); s.setString (1, "De'Mont"); s.setString (2, "1973-01-12"); s.setNull (3, java.sql.Types.CHAR); s.setString (4, "eggroll"); s.setInt (5, 4); count = s.executeUpdate ( ); s.close ( ); // close statement?? ? ? b）：Use a quoting function if your API provides one for converting data values to a safe form that is suitable for use in query strings.?
//PHP3還不支持null function sql_quote ($str) {return (isset ($str) ? "'" . addslashes ($str) . "'" : "NULL"); }//PHP4后 function sql_quote ($str) {return (isset ($str) ? "'" . mysql_escape_string ($str) . "'" : NULL); }unset ($null); # create a "null" value $stmt = sprintf ("INSERT INTO profile (name,birth,color,foods,cats)VALUES(%s,%s,%s,%s,%s)",sql_quote ("De'Mont"),sql_quote ("1973-01-12"),sql_quote ($null),sql_quote ("eggroll"),sql_quote (4)); $result_id = mysql_query ($stmt, $conn_id);//轉換后的SQL語句 INSERT INTO profile (name,birth,color,foods,cats) VALUES('De\'Mont','1973-01-12',NULL,'eggroll','4')

6、注意：NULL的特殊性( like '%' ; not like '%' ; regexp '.*' ; not regexp '.*' 全都不能匹配)

如下表和數據：

DROP TABLE IF EXISTS taxpayer; CREATE TABLE taxpayer (name VARCHAR(20),id VARCHAR(20) );INSERT INTO taxpayer (name,id) VALUES('bernina', '198-48'); INSERT INTO taxpayer (name,id) VALUES('bertha', NULL); INSERT INTO taxpayer (name,id) VALUES('ben', NULL); INSERT INTO taxpayer (name,id) VALUES( NULL, '475-83'); INSERT INTO taxpayer (name,id) VALUES( 'baidu', '111+55');假設我要查詢，id匹配如下模式：“包含-”

mysql> select * from taxpayer where id like '%-%'; +---------+--------+ | name | id | +---------+--------+ | bernina | 198-48 | | NULL | 475-83 | +---------+--------+這里id為NULL的沒有匹配（正確），但是如果我用{ id not like '%-%' }，按照 一般思維“要么匹配，要么不匹配”應該可以查出所有不匹配的，但 實際是id為NULL還是不再查詢結果中！

mysql> select * from taxpayer where id not like '%-%'; +-------+--------+ | name | id | +-------+--------+ | baidu | 111+55 | +-------+--------+可見對NULL要做特殊處理，{ id like '%-%' }全集的補集為{ id not like '%-%' or id is NULL }

mysql> select * from taxpayer where id not like '%-%' or id is null; +--------+--------+ | name | id | +--------+--------+ | bertha | NULL | | ben | NULL | | baidu | 111+55 | +--------+--------+
正則表達式的處理結果一樣，結果如下：

mysql> select * from taxpayer where id regexp '[0-9]{3}\-[0-9]{2}'; +---------+--------+ | name | id | +---------+--------+ | bernina | 198-48 | | NULL | 475-83 | +---------+--------+ mysql> select * from taxpayer where id not regexp '[0-9]{3}\-[0-9]{2}'; +-------+--------+ | name | id | +-------+--------+ | baidu | 111+55 | +-------+--------+ mysql> select * from taxpayer where id not regexp '[0-9]{3}\-[0-9]{2}' or id is null; +--------+--------+ | name | id | +--------+--------+ | bertha | NULL | | ben | NULL | | baidu | 111+55 | +--------+--------+

7、MySQL時區，column為 TIMESTAMP 時，'1970-01-01 00:00:00' 無法插入問題。

（參考：http://www.cnblogs.com/lexus/archive/2010/11/30/1892231.html）

MySQL 時區默認是服務器的時區。
可以通過以下命令查看

mysql> show variables like '%time_zone%'; +------------------+--------+ | Variable_name | Value | +------------------+--------+ | system_time_zone | | | time_zone | SYSTEM | +------------------+--------+可以通過修改my.cnf
在 [mysqld] 之下加

default-time-zone=timezone?
來修改時區。如：
default-time-zone = '+8:00'
改了記得重啟msyql喔
注意一定要在 [mysqld] 之下加 ，否則會出現 unknown variable 'default-time-zone=+8:00'

另外也可以通過命令 set time_zone = timezone
比如北京時間（GMT+0800）
set time_zone = '+8:00';
這個和php的時區設置又有點差別，比如北京時間在php中是
date_default_timezone_set('Etc/GMT-8');

美國pst時間（GMT-08:00）

set time_zone = '-8:00';

#默認時區，time_zone='+8:00' mysql> select now(); +---------------------+ | now() | +---------------------+ | 2011-07-21 11:52:00 | +---------------------+mysql> set time_zone='+0:00';mysql> select now(); +---------------------+ | now() | +---------------------+ | 2011-07-21 03:52:18 | +---------------------+
如下表和數據，'1970-01-01 00:00:00' 無法插入

DROP TABLE IF EXISTS timestamp_val; CREATE TABLE timestamp_val (ts TIMESTAMP );INSERT INTO timestamp_val (ts) VALUES('1970-01-01 00:00:00'); INSERT INTO timestamp_val (ts) VALUES('1987-03-05 12:30:15'); INSERT INTO timestamp_val (ts) VALUES('1999-12-31 09:00:00'); INSERT INTO timestamp_val (ts) VALUES('2000-06-04 15:45:30');

ERROR 1292 (22007): Incorrect datetime value: '1970-01-01 00:00:00' for column 'ts' at row 1

我考慮到可能是時區的問題，就設置 time_zone='+0:00' 依然無法插入，'1970-01-01 00:00:01' 能插入！費解！！！

8、TIMEDIFF 函數有最大差值限制（838:59:59）；TIMESTAMPDIFF無限制

范圍以內，正確：

mysql> select timediff('2011-10-21 14:25:00','2011-10-02 10:12:22'); +-------------------------------------------------------+ | timediff('2011-10-21 14:25:00','2011-10-02 10:12:22') | +-------------------------------------------------------+ | 460:12:38 | +-------------------------------------------------------+

范圍以外，錯誤：

mysql> select timediff('2011-10-21 14:25:00','2011-01-02 10:12:22'); +-------------------------------------------------------+ | timediff('2011-10-21 14:25:00','2011-01-02 10:12:22') | +-------------------------------------------------------+ | 838:59:59 | +-------------------------------------------------------+ mysql> select timediff('2011-10-21 14:25:00','2001-10-02 10:12:22'); +-------------------------------------------------------+ | timediff('2011-10-21 14:25:00','2001-10-02 10:12:22') | +-------------------------------------------------------+ | 838:59:59 | +-------------------------------------------------------+

TIMESTAMPDIFF 示例：

mysql> set @dt1 = '1900-01-01 00:00:00',@dt2='1910-01-01 00:00:00';mysql> select-> timestampdiff(second, @dt1, @dt2) as seconds,-> timestampdiff(minute, @dt1, @dt2) as minutes,-> timestampdiff(hour, @dt1, @dt2) as hours,-> timestampdiff(day, @dt1, @dt2) as days,-> timestampdiff(week, @dt1, @dt2) as weeks,-> timestampdiff(year, @dt1, @dt2) as years; +-----------+---------+-------+------+-------+-------+ | seconds | minutes | hours | days | weeks | years | +-----------+---------+-------+------+-------+-------+ | 315532800 | 5258880 | 87648 | 3652 | 521 | 10 | +-----------+---------+-------+------+-------+-------+

9、NULL 的特殊性！

A、排序時，asc（默認值）NULL在頭，desc NULL在尾

示例--如下表和數據

DROP TABLE IF EXISTS taxpayer; CREATE TABLE taxpayer (name VARCHAR(20),id VARCHAR(20) );INSERT INTO taxpayer (name,id) VALUES('bernina', '198-48'); INSERT INTO taxpayer (name,id) VALUES('bertha', NULL); INSERT INTO taxpayer (name,id) VALUES('ben', NULL); INSERT INTO taxpayer (name,id) VALUES( NULL, '475-83'); INSERT INTO taxpayer (name,id) VALUES( 'baidu', '111+55');操作

mysql> select * from taxpayer order by id; +---------+--------+ | name | id | +---------+--------+ | bertha | NULL | | ben | NULL | | baidu | 111+55 | | bernina | 198-48 | | NULL | 475-83 | +---------+--------+ mysql> select * from taxpayer order by id desc; +---------+--------+ | name | id | +---------+--------+ | NULL | 475-83 | | bernina | 198-48 | | baidu | 111+55 | | bertha | NULL | | ben | NULL | +---------+--------+當然也可以特殊處理，將NULL永遠放在尾巴處（詳見：Recipe 7.14. Floating Values to the Head or Tail of the Sort Order）

mysql> select * from taxpayer order by if(id is null,1,0), id; +---------+--------+ | name | id | +---------+--------+ | baidu | 111+55 | | bernina | 198-48 | | NULL | 475-83 | | bertha | NULL | | ben | NULL | +---------+--------+
B、Most aggregate functions ignore NULL values.（COUNT()、MIN()、MAX()、AVG()、SUM()）

（詳見：Recipe 8.8. Summaries and NULL Values）

示例--如下表和數據

DROP TABLE IF EXISTS expt;CREATE TABLE expt (subject VARCHAR(10),test VARCHAR(5),score INT );INSERT INTO expt (subject,test,score) VALUES('Jane','A',47); INSERT INTO expt (subject,test,score) VALUES('Jane','B',50); INSERT INTO expt (subject,test,score) VALUES('Jane','C',NULL); INSERT INTO expt (subject,test,score) VALUES('Jane','D',NULL); INSERT INTO expt (subject,test,score) VALUES('Marvin','A',52); INSERT INTO expt (subject,test,score) VALUES('Marvin','B',45); INSERT INTO expt (subject,test,score) VALUES('Marvin','C',53); INSERT INTO expt (subject,test,score) VALUES('Marvin','D',NULL);操作

mysql> select subject,-> count(score) as n,-> sum(score) as total,-> avg(score) as average,-> min(score) as lowest,-> max(score) as hightest-> from expt group by subject; +---------+---+-------+---------+--------+----------+ | subject | n | total | average | lowest | hightest | +---------+---+-------+---------+--------+----------+ | Jane | 2 | 97 | 48.5000 | 47 | 50 | | Marvin | 3 | 150 | 50.0000 | 45 | 53 | +---------+---+-------+---------+--------+----------+ 實際處理的數據只有2+3=5條！NULL都被忽略了！

如果計算的集合為 empty 或集合內的值都為 NULL ，則計算后的結果也為 NULL 。

mysql> select subject,-> count(score) as n,-> sum(score) as total,-> avg(score) as average,-> min(score) as lowest,-> max(score) as hightest-> from expt where score is null group by subject; +---------+---+-------+---------+--------+----------+ | subject | n | total | average | lowest | hightest | +---------+---+-------+---------+--------+----------+ | Jane | 0 | NULL | NULL | NULL | NULL | | Marvin | 0 | NULL | NULL | NULL | NULL | +---------+---+-------+---------+--------+----------+

10、group by 后排序 ， 直接在后邊加 order by xxx 即可。

mysql> select-> monthname(statehood) as month,-> dayofmonth(statehood) as day,-> count(*) as count-> from states group by month , day having count>1; +----------+------+-------+ | month | day | count | +----------+------+-------+ | February | 14 | 2 | | June | 1 | 2 | | March | 1 | 2 | | May | 29 | 2 | | November | 2 | 2 | +----------+------+-------+ mysql> select-> monthname(statehood) as month,-> dayofmonth(statehood) as day,-> count(*) as count-> from states group by month , day having count>1 order by day; +----------+------+-------+ | month | day | count | +----------+------+-------+ | June | 1 | 2 | | March | 1 | 2 | | November | 2 | 2 | | February | 14 | 2 | | May | 29 | 2 | +----------+------+-------+

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